【摘要】 采用真空座滴法研究了基体表面粗糙度（R_a）对AgCu-4.3 at%Ti/Al₂O₃和AgCu-4.3 at%Ti/石墨两个体系润湿性能的影响,其中Al₂O₃的R_a为256⁶36 nm,石墨的R_a为265¹898 nm。结果表明,基体粗糙度对界面反应层厚度及其侧向生长、润湿动力学和最终润湿角（θ_f）均有很大影响。在1200 K的润湿温度下,随着基体R_a的增加,两个润湿体系的最终润湿角均呈上升趋势;高温反应性润湿体系润湿性的好坏取决于界面反应产物的侧向生长,当基体表面粗糙度增加时,增加了金属液体中活性元素向产物侧向生长前沿扩散的距离,同时粗糙表面的轮廓峰会对三相线的移动产生钉扎作用,因此界面反应产物侧向生长受到抑制;活性元素更易于向界面处扩散,生成更厚的界面反应产物层;当活性金属液体在粗糙表面润湿时,具有相对缓慢的润湿速度,达到润湿平衡的时间也较短,最终导致较大的润湿角。更多还原

【Abstract】 Effects of substrate roughness( R_a ) on wettability of metal/ceramic combound-forming wetting systems were investigated by sessile drop technique at high temperature. The AgCu-4. 3 at% Ti / alumina and AgCu-4. 3 at% Ti / graphite wetting systems were selected,the R_a range used for alumina is 256-636 nm,and 265-1898 nm for graphite. The results show that the substrate roughness has strong effect on the thickness and lateral growth of the interfacial reaction product layer,wetting kinetics and the final contact angle( θ_f). The θ_f of the two systems increases with the increasing of R_a at 1200 K. The wettability of the reactive metal / ceramic system depends on the lateral growth of reaction product layer. With the increase of substrate roughness,the diffusion distance of the reactive element moving to the lateral growth front is actually increased,and the movement of triple line is also delayed by the asperities of rough surface,which restrained the lateral growth of the product layer. Meanwhile,the reactive element Ti tends to move to the interface region,leading to the increase of the interfacial product layer. Wetting on rough surface exhibits the slow spreading and a short period of spreading time,resulting in the increase in θ_f.更多还原